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51.
Decreased ATP-sensitive K(+) current density during chronic human atrial fibrillation 总被引:3,自引:0,他引:3
Balana B Dobrev D Wettwer E Christ T Knaut M Ravens U 《Journal of molecular and cellular cardiology》2003,35(12):1399-1405
Chronic atrial fibrillation (AF) is associated with shortening of action potential duration (APD), which involves modified activity of atrial ion currents. However, little is known about the activity of ATP-sensitive K(+) channels (I(K,ATP)) during chronic AF. An AF-related increase in the activity of I(K,ATP) would reduce APD and could contribute to initiation and/or perpetuation of AF. Here, we studied the activity of I(K,ATP) in atrial myocytes from patients with sinus rhythm (SR) and chronic AF. Human atrial myocytes were isolated from atrial tissue obtained from patients undergoing open-heart surgery. Inward rectifier currents were measured with the whole-cell patch-clamp technique by applying a depolarizing ramp pulse (1245 ms) from -100 to +40 mV (0.5 Hz). I(K,ATP) was activated with the I(K,ATP) channel opener rilmakalim. The inward rectifier I(K1) and I(K,ATP) were identified by their sensitivity to 1 mM Ba(2+). Density of I(K1) did not differ between cells from patients with AF (at -100 mV: -14.8 +/- 1.3 pA/pF, n = 38/10 (cells/patients)) and SR (-13.8 +/- 1.5 pA/pF, n = 33/16). In both types of cells, rilmakalim stimulated I(K,ATP) (defined as rilmakalim-inducible current) in a concentration-dependent manner (0.3-10 microM). However, maximum activation of I(K,ATP) with 10 microM rilmakalim was smaller in AF than in SR cells (at -100 mV: -5.3 +/- 0.8 pA/pF, n = 22/7 vs. -11.2 +/- 2.9 pA/pF, n = 19/9; at +40 mV: +9.6 +/- 2.1 pA/pF, n = 22/7 vs. +23.7 +/- 3.4 pA/pF, n = 19/9 for AF and SR, respectively; P < 0.05). Only aortic valve disease and pulmonary hypertension were found to be independent contributors to I(K,ATP) current density. We provide evidence that chronic AF is associated with a downregulation of ATP-sensitive K(+) currents. These changes may provide an additional molecular mechanism for electrical remodeling in chronic AF. 相似文献
52.
53.
Leddy Anna M. Neilands Torsten B. Twine Rhian Kahn Kathleen Ahern Jennifer Pettifor Audrey Lippman Sheri A. 《AIDS and behavior》2022,26(5):1347-1354
AIDS and Behavior - We previously demonstrated that village community mobilization (CM) was associated with reduced HIV incidence among adolescent girls and young women (AGYW) in South Africa.... 相似文献
54.
Richter CM Godes M Wagner C Maser-Gluth C Herzfeld S Dorn M Priem F Slowinski T Bauer C Schneider W Neumayer HH Kurtz A Hocher B 《Journal of hypertension》2004,22(1):191-198
BACKGROUND: It has been shown that the macula densa participates in the regulation of increased renin expression in two-kidney one-clip (2K1C) renovascular hypertension. Prostaglandins might be one of the mediators of macula densa function, because the cyclooxygenase-2 (COX-2), one of the rate-limiting enzymes of the prostaglandin pathway, is upregulated in 2K1C renovascular hypertensive rats. We tested the effect of chronic COX-2 inhibition on blood pressure, urinary aldosterone excretion and kidney morphology, as well as kidney function. METHODS: Four groups were established: two groups of 2K1C renovascular hypertensive rats treated with the specific COX-2 inhibitor Celecoxib (cele) (15 mg/kg per day) or placebo immediately after operation, and two sham-operated control groups fed with Celecoxib or placebo. RESULTS: Long-term COX-2 inhibition in 2K1C renovascular hypertensive rats did not alter blood pressure at any point of time. Urinary aldosterone excretion was elevated by clipping the renal artery (2K1C, 8.1 +/- 1.9, versus controls, 3.6 +/- 0.5 ng/24 h; P = 0.05) but was not influenced by treatment with Celecoxib. Also, Celecoxib treatment did not alter glomerular filtration rate (GFR), serum sodium, serum creatinine, serum urea or proteinuria in 2K1C renovascular hypertensive rats. Interstitial fibrosis of the left clipped kidney was markedly reduced (2K1C, 6.19 +/- 0.83% versus 2K1C + cele 3.00 +/- 0.68% of total area; P = 0.012), whereas the interstitial fibrosis of the non-clipped kidney or the glomerulosclerosis of both kidneys were not affected by Celecoxib treatment. CONCLUSIONS: Celecoxib reduces the interstitial fibrosis of the clipped kidney. Blood pressure, urinary aldosterone excretion or whole kidney function were not affected in renal hypertensive rats. 相似文献
55.
Why HIV Infections Have Increased Among Men Who Have Sex with Men and What to Do About It: Findings from California Focus Groups 总被引:3,自引:0,他引:3
Morin SF Vernon K Harcourt JJ Steward WT Volk J Riess TH Neilands TB McLaughlin M Coates TJ 《AIDS and behavior》2003,7(4):353-362
A resurgence of sexual risk taking, STDs, and HIV incidence has been reported among men who have sex with men (MSM) in several countries. We asked 113 MSM in 12 focus groups conducted in five California cities to identify factors leading to increased risk taking and assess prevention messages to reduce risk in this population. Participants perceived that HIV risk taking has increased because (1) HIV is not the threat it once was due to more effective therapies, (2) MSM communicate less about HIV, and social support for being safe has decreased, and (3) community norms have shifted such that unsafe sex is more acceptable. The prevention messages ranked most likely to motivate risk reduction encouraged individuals to seek social support from friends. Themes ranked least likely to succeed were those that described the negative consequences of HIV or reinforced existing safer sex messages. 相似文献
56.
Groth Olwen Franz Simon Fels Helena Krueger Julia Roider Gabriele Dame Torsten Musshoff Frank Graw Matthias 《Forensic Toxicology》2022,40(1):144-155
Forensic Toxicology - In forensics, entomological specimens can be used as additional/alternative matrices to detect xenobiotics when human specimens are limited in their application. Despite some... 相似文献
57.
Following an acute myocardial infarction, the size of the infarct and the resulting left ventricular volume and function are important predictors of mortality. Identifying patients with impaired tissue level perfusion after percutaneous coronary intervention (PCI) for myocardial infarction therefore could have prognostic implications. To obtain combined measures of left ventricular perfusion, volumes and function we applied a gated myocardial perfusion imaging by (99m)Tc-sestamibi single photon emission computerized tomography to 19 patients immediately after revascularization by PCI and repeated this after 3 months. The results of the acute myocardial perfusion imaging significantly correlated to final infarct size, left ventricular volumes and function 3 months later. It is concluded that the method holds the potential for risk stratifying patients immediately after revascularization for acute myocardial infarction. 相似文献
58.
Ilgar Aghalarov Torsten Herzog Waldemar Uhl Orlin Belyaev 《HPB : the official journal of the International Hepato Pancreato Biliary Association》2018,20(7):676-683
Background
Double-loop (DL) reconstruction after pancreaticoduodenectomy (PD), diverting pancreatic from biliary secretions, has been reported to reduce rates and severity of postoperative pancreatic fistula (POPF) compared to single loop (SL) reconstruction at the price of prolonged operative duration. This study investigated the feasibility of a new reconstruction method combining the advantages of DL with the simplicity of SL in patients with high-risk pancreas.Methods
A modified single-loop (mSL) reconstruction was used in patients undergoing PD with a soft pancreatic remnant and a pancreatic duct smaller than 3 mm (n = 50). The loop between the pancreatic and the biliary anastomoses was left longer and a side-to-side jejunojejunal anastomosis was performed between them at the lowest point to promote isolated flow of pancreatic and biliary secretions. Rate and severity of POPF, mortality, duration of surgery, and POPF-associated morbidity were compared to those of 50 matched patients with SL and 25 patients with DL reconstruction.Results
Duration of surgery was 57 min longer for DL, but equal for mSL and SL. The POPF rate did not differ between the three groups. The severity of POPF was more pronounced in the SL group (62% grade C: p = 0.011). Mortality and major morbidity were lower and hospital stay shorter in the mSL and DL groups compared to the SL group.Conclusions
The new mSL reconstruction was safer than conventional SL and faster to perform than DL reconstruction in patients with a high-risk pancreas. It did not influence the rate of POPF, but reduced its severity, leading to less major morbidity and mortality. 相似文献59.
Torsten Leif Bunk Lauritsen Niels Grunnet Allan Rasmussen Niels Henry Secher Bj?rn Quistorff 《Journal of hepatology》2002,36(1):99-104
BACKGROUND/AIMS: The liver is regarded the most important source of glucose production and it is common practice to administer glucose during human liver transplantations to avoid hypoglycaemia. The purpose of this study was to evaluate the importance of extra-hepatic contribution (kidney, gut and muscle) to the glucose homeostasis in the anhepatic pig and in man during the anhepatic phase of human liver transplantations. METHODS: Blood glucose and lactate were monitored in the anhepatic phase in 46 patients undergoing liver transplantation. Arterial-venous differences of lactate, glucose, glycerol, alanine and free fatty acids were measured over kidney, gut and hind leg in 18 pigs made anhepatic. RESULTS: Blood glucose did not change significantly and blood lactate increased only marginally during the anhepatic phase of human orthotopic liver transplantation. In the anhepatic pig, however, blood glucose decreased with a halflife of about 26 min and blood lactate increased. Kidney gluconeogenesis was 0.116+/-0.016 mmol min(-1). Fifty percent of kidney glucose output could be accounted for by lactate- and glycerol uptake. CONCLUSIONS: The results show that in humans extra hepatic gluconeogenesis is sufficient to maintain normal blood glucose in the anhepatic phase of orthotopic liver transplantation, while in the pig this was not the case. 相似文献
60.
Grarup N Andreasen CH Andersen MK Albrechtsen A Sandbaek A Lauritzen T Borch-Johnsen K Jørgensen T Schmitz O Hansen T Pedersen O 《The Journal of clinical endocrinology and metabolism》2008,93(6):2294-2299
CONTEXT: Hepatic lipase plays a pivotal role in the metabolism of high-density lipoprotein (HDL) and low-density lipoprotein by involvement in reverse cholesterol transport and the formation of atherogenic small dense low-density lipoprotein. OBJECTIVES: The objective was to investigate the impact of variants in LIPC on metabolic traits and type 2 diabetes in a large sample of Danes. Because behavioral factors influence hepatic lipase activity, we furthermore examined possible gene-environment interactions in the population-based Inter99 study. DESIGN: The LIPC -250G>A (rs2070895) variant was genotyped in the Inter99 study (n = 6070), the Anglo-Danish-Dutch Study of Intensive Treatment in People with Screen Detected Diabetes in Primary Care Denmark screening cohort of individuals with risk factors for undiagnosed type 2 diabetes (n = 8662), and in additional type 2 diabetic patients (n = 1,064) and glucose-tolerant control subjects (n = 360). RESULTS: In the Inter99 study, the A allele of rs2070895 associated with a 0.057 mmol/liter [95% confidence interval (CI) 0.039-0.075] increase in fasting serum HDL-cholesterol (HDL-c) (P = 8 x 10(-10)) supported by association in the Anglo-Danish-Dutch Study of Intensive Treatment in People with Screen Detected Diabetes in Primary Care study [0.038 mmol/liter per allele (95% CI 0.024-0.053); P = 2 x 10(-7)). The allelic effect on HDL-c was modulated by interaction with self-reported physical activity (P(interaction) = 0.002) because vigorous physically active homozygous A-allele carriers had a 0.30 mmol/liter (95% CI 0.22-0.37) increase in HDL-c compared with homozygous G-allele carriers. CONCLUSIONS: We validate the association of LIPC promoter variation with fasting serum HDL-c and present data supporting an interaction with physical activity implying an increased effect on HDL-c in vigorous physically active subjects carrying the -250 A allele. This interaction may have potential implications for public health and disease prevention. 相似文献